...Diffusion is defined as the random movement of molecules from an area of higher concentration to areas of lower concentration. Osmosis is a special type of diffusion in which water moves from high to lower concentration through a selectively permeable membrane. If for some reasons two solutions have same level of concentration no movement take place and such solutions are called isotonic. If the solutions have different levels of concentration then the area with higher concentration is called hypertonic and the area with lower concentration is called hypotonic. This experiment was conducted to observe the osmosis process. In this experiment dialysis tubbing served as the permeable membrane. The weight of the dialysis bags is taken one time before putting them into the solution and once after soaking the bag into another solution for about the hour. The weight of the bag determined the movement of the molecules from higher to lower concentration. Hypothesis: for this experiment three hypothesis were made: 1. For test one it was expected that the water molecules will enter the dialysis bag 2. For test two it was expected that the water molecules will move out from the dialysis bag 3. For test three it was expected that the water molecules will move into the dialysis bag Material:...
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...diffusing across a membrane? requires passive transport requires no energy requires active transport requires both a and b Which correctly describes the plasma membrane? fluid and nonpermeable rigid and nonpermeable fluid and partially permeable fluid and completely permeable Which component of the phospholipid bilayer is considered hydrophobic? phospholipid head phospholipid tail phospholipid head and tail none of the above Which correctly describes the fluid-mosaic model of the cell membrane? phospholipid monolayer with embedded proteins phospholipid bilayer with embedded proteins phospholipid monolayer with embedded triglycerides cholesterol bilayer with embedded proteins This process uses a carrier protein...
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...Diffusion. Diffusion is the movement of substances within a fluid from a region of higher concentration to a region of lower concentration. Phagocytosis. Phagocytosis is a process of accumulating particles into the cell. It involves the movement of dissolved molecules across the cell membrane from a region of lower concentration to a region of higher concentration. 2 Amino acids are larger molecules and a charged atom so they cannot diffuse easily through the phospholipids layer. It requires facilitated diffusion. Water is smaller than almost all other molecules and it can cross the membrane by osmosis. Alcohol is a small molecule and an uncharged atom so it can dissolve easily through the phospholipids layer by diffusion. Bacteria is one of the smallest organism so it uses phagocytosis which is a specialized form of endocytosis as a means to enter the cell. 3 The facilitated diffusion is a passive process so it does not require any energy for its transport. Osmosis is a passive process so it does not require any energy for its transport. Diffusion is a passive process so it does not require any energy for its transport. Phagocytosis is an active process so it requires energy for its transport. Reference:- Internet (Wikipedia, ScienceDirect) and As & A2 Biology...
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...require energy, diffusion, facilitated diffusion and osmosis are included in this. Active transport is a process which does need energy to function. Endocytosis and exocytosis are examples of this. Diffusion and the factors affecting how well it can occur will also be talked about. http://chemwiki.ucdavis.edu/@api/deki/files/26918/=17.6.new.jpg?revision=1 The phospholipid bilayer is a structural component that makes up all cell membranes. The lipid bilayer is named so because there are two layers of fat cells within the membrane. They are made up of a glycerol backbone with a phosphate group and two fatty acid chains attached to it. The phosphate group is polar while the fatty acids are no polar. Phospholipids are the main molecules found in the plasma membrane. The plasma membrane protects the interior of the cell which also has selective permeability. Most of the cell membrane is impenetrable to water soluble substances as it’s made up of lipids. Those water soluble substances and other molecules can pass through the membrane when it is made up of proteins. They can pass through by a channel protein or carrier protein. Cells need a membranes in order to control what substances go in and out. It also compartmentalises individual cell processes by containing the contents and organelles of the cells. Because of the bilayer, communication with the external environment can be achieved. This is also the site where many chemical reactions can take place. The membrane can allow the...
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...There are different mechanisms used by the body to transport substances across the cell membrane. One of these methods is called Simple diffusion. Simple diffusion involves molecules diffusing from an area of higher concentration to an area of lower concentration. Simple diffusion happens through random movement of particles through the cell membrane. Carbon dioxide and other gases such as oxygen and ethanol uses simple diffusion as a method of cell transportation. Several factors affect the rate of diffusion including high temperatures and the size of the molecule. A smaller molecule will diffuse much quicker than a larger one as it is able to move about without difficulty. Concentration gradient and the distance of diffusion also makes a...
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...two layers of phospholipids that make up the membrane. It confines the cell organelles from the extracellular area. The cell can manage its own environment. The phospholipid bilayer controls what enters and exits the cell, with the aid of transporter proteins and channels. However if the internal cell environment is not performing correctly then the channels will...
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...experiment, you will explore the cell membrane’s role in allowing materials to enter or leave the cell. This is a vital function of the cell membrane. Using the Physio Ex CD 9.0, you will be able to conduct experiments showing the important cell membrane processes of diffusion, osmosis, filtration, and active transport. The simulations will allow you to alter conditions to show the effect of concentrations, pore size, pressure, carrier, and ATP have on movements of materials through the cell membrane. Purpose: To conduct experiments showing the effects of concentration, ions, and particle size of movement through the cell membrane. Materials: Lab manual, PhysioEx 9.0 Procedure: Cell Transport Mechanisms and Permeability in the lab manual. You will also need the PhysioEx 9.0 CD for this lab. Read over exercise overview and introduction. Complete the following questions from the exercise as you complete the simulation exercises. Go to Exercise 1 Cell Transport Mechanisms and Permeability on the CD. Follow the directions and complete each part. Answer questions or fill in tables as you proceed through the experiment. Place your answers in the spaces provided below. Submit your lab in Moodle. Activity 1. Simple Diffusion Chart 1 |Chart 1 Dialysis Results(average diffusion rate in mM/min | | |...
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...all of which play a vital role within the body. Each component has its own specific role that it performs in order for the cell to function and maintains the cell membrane. The main components of the cell include the cell membrane, cytoplasm, the nucleus, nucleolus, nuclear membrane, endoplasmic reticulum (smooth ER and rough ER), mitochondria, Golgi apparatus, lysosomes, ribosomes and vacuoles. The cell membrane – The cell membrane otherwise known as the plasma membrane is located on the surface of a typical animal cell. The cell membrane is made up of a phospholipid bilayer and is a selectively permeable membrane that allows substances to pass in and out of the cell. This selectively permeable membrane means that only water, gases and other nutrients are able to pass through whilst keeping toxins out. The lipid bilayer of the cell membrane aids in the protection of the cell, as it helps to control the movement of particles that pass in and out of the cell. The structure of the phospholipid is made up of hydrophilic heads and hydrophobic tails. Cytoplasm – The cytoplasm is a gel-like substance that is clear in colour made up of 80% water and also contains enzymes, salts, organelles and other organic molecules. It consists of all the contents outside of the nucleus and is encased within the cell membrane. The cytoplasm aids in moving materials around the cell, and is a solvent that allows nutrients and waste products within it to dissolve. The organelles inside of...
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...University of Phoenix Material Cell Structures Complete the following charts comparing prokaryotes and eukaryotes, plant and animal cells, and cells and viruses. Prokaryotes and Eukaryotes |Prokaryotes: unique structures |Common structures |Eukaryotes: unique structures | |Capsule |Cell Membrane |Plasma Membrane | |Cell WALL |Cell Wall |Nucleus | |Cytoplasm |Cilia |Nucleolus | |Cell Membrane | Flagella |Endoplasmic reticulum | | Plasma Membrane | |Golgi Complex | |PILI | |Lysosomes | |Flagella | |Vacuoles | |Ribosomes | |Mitochondria | |Plasmids ...
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...hapter 5 1. Describe the fluid mosaic structure of cell membranes. The fluid mosaic model is used to describe a membrane’s structure divers protein molecules suspended in a fluid phospholipid bilayer. This molecule illustrates the structure and function a plasma membrane, the boundary that encloses a living cell. 2. What are the functions of membrane proteins? 3. How are phospholipid molecules arranged in the plasma membrane? How does this arrangement affect the structure and properties of cell membranes (including the plasma membrane)? 4. What is diffusion? Diffusion is a tendency of particles to spread out evenly in an available space. 5. What is passive transport? The diffusion of a substance across a biological membrane with no expenditure of energy 6. Define osmosis. The diffusion of free water across a selectively permeable membrane. 7. Distinguish between hypertonic, hypotonic, and isotonic solutions. Hypertonic the solute concentration is higher outside the cell, water molecules move out of the cell, and the cell will shrink. Hypotonic the solute concentration is lower outside the cell, water molecules move into the cell, and the cell will expand and may burst. Isotonic the concentration of solute is the same on both sides of a membrane, and the cell volume will not change. 8. Distinguish between exocytosis, endocytosis, phagocytosis, and receptor-mediated endocytosis. Exocytosis is used to export bulky molecules,...
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...length and mass of the potato. What is osmosis? Osmosis is the movement of the water molecules across a partially permeable from a region of high water concentration to a region of low water concentration. Osmosis is a special case of diffusion The biochemical process in living cells always takes place in a solution. A solution is made up of a solvent (the dissolving fluid) and solute (the particles dissolved in the solvent). In living organisms, the solvent is water and the solution is called aqueous solution. Living cells are separated from their surroundings by the partially permeable cell surface membrane. The contents of the cell, the cytoplasm, are one aqueous solution and the surroundings of the cell, for example pond water, is another aqueous solution. If the two solutions do not have the same concentration of various substances, molecules may move away from one to the other by diffusion, if the membrane is permeable these substances. To summarise osmosis: The diffusion of water molecules, down a water potential gradiant across a partially permeable membrane. Cells and osmosis A cell is surrounded by a partially permeable membrane, and water may cross the membrane easily. If cell is placed in a solution of lower water potential, water leaves the cell by osmosis. If the cell is placed in a solution of higher water potential, water enters by osmosis. Plant cells and osmosis When water enters a plant...
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...types of transports for passive and two types of transports for active. The three types of passive transports are diffusion, osmosis, and facilitated diffusion. The two types of active transports are endocytosis, and exocytosis. Passive transport does not require ATP, also known as energy. The reason it does not require energy is because it travels down a concentration gradient. This means molecules naturally travel from high to low concentration. The first type of passive transport is diffusion. Diffusion is the movement of molecule across the membrane from high to low concentration. Diffusion naturally occurs until equilibrium is reached. Only very small molecules can cross the membrane in diffusion. These include ions, gases, alcohols, and small lipids. The next type of passive transport is osmosis. Osmosis is the diffusion of water across the cell membrane. Three examples of osmosis are hypertonic, hypotonic, and isotonic solutions. A hypertonic solution is a solution that has a higher concentration of dissolved particles than another solution. A hypotonic solution is a solution that has lower concentration of dissolved particles compare to another solution. Lastly an isotonic solution is a solution that has an equal concentration of dissolved particles compared to another solution. The last type of passive transport is facilitated diffusion. In facilitated diffusion...
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...Compare the structure of prokaryotic and eukaryotic. (290) There are two major types of cell: eukaryotic and prokaryotic. Eukaryotic cells have many membrane-bounded organelles within the cell. Whereas prokaryotic cells do not have any membrane-bounded organelles. The only membrane in prokaryotic is plasma(cell)membrane. Prokaryotes with the size of 5㎛(1-10㎛) are much smaller than eukaryotic cells with the size of 10㎛(10-100㎛). They both have a cell wall but with different composition. Prokaryotic cell walls are combined of peptidoglycan, a single large polymer of amino acids and sugar. Whereas the cell wall in plant is cellulose and fungi’s cell wall is made of chitin (the cell wall are not present in animals cells). Both cell types have many ribosomes, but the ribosomes of the eukaryotic are more complex and larger(80S) than ribosomes in the prokaryotic cell(70S). The ribosomes makes protein in both and can be found floating within the cytoplasm and RER (only in eukaryotic cells). Both cells have DNA as their genetic material, but the DNA of eukaryotes is held within its nucleus.Eukaryotic DNA is linear and is associated with histones (proteins). Hence the nucleus is absent in...
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...CELL CELL MEMBRANE: What are cell membranes made of? PHOSPHOLIPIDS & PROTEINS How are membranes arranged? PHOSPHOLIPIDS make a BILAYER with POLAR HEADS FACING OUT and HYDROPHOBIC TAILS FACING IN Which molecule in cell membranes helps cells recognize “self”? GLYCOPROTEINS What is the cell membrane’s function? CONTROLS WHAT ENTERS AND LEAVES CELL; HOMEOSTASIS What do we call membranes that allow certain molecules pass through and keep others out? = SELECTIVELY PERMEABLE NUCLEUS: What is the nucleus like? Has a DOUBLE MEMBRANE and CONTAINS DNA What structure surrounds the DNA and controls what enters and leaves the nucleus? : NUCLEAR MEMBRANE What is the dark spot in the nucleus called? NUCLEOLUS What is the job of the nucleolus? MAKES RIBOSOMES What do we call DNA that is TIGHTLY PACKED in DIVIDING CELLS? = CHROMOSOMES What do we call DNA that is SPREAD OUT in NON-DIVIDING CELLS? = CHROMATIN What is the function of the nucleus? CONTROL CENTER of cell; CONTAINS DNA CYTOPLASM: What is the gel-like material and organelles called inside the cell membrane? CYTOPLASM MITOCHONDRIA: Looks like/Made of ?: Have a DOUBLE MEMBRANE and OWN DNA What is the folded inner membrane called? = CRISTAE What is the function of mitochondria? POWERPLANT What molecules is burned for fuel in mitochondria? BURNS GLUCOSE Mitochondria store the energy released from burning glucose as which molecule? ATP GOLGI BODIES: Made of: MEMBRANE SACS Looks like:...
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...There’s different types of movements which go across the cell membrane. One of the transport is a passive transport which is movements across the cell membrane this doesn’t require any energy which is dependent on the permeability of the cell membrane. There are 3 different main roles in passive transport which are called Diffusion, Osmosis, and finally facilitated diffusion. There are different job roles in the passive transport for example in Diffusion the movements of each molecule from the region goes from a high concentration to a low concentration. Another diffusion which is called “Facilitated diffusion” this process doesn’t require ATP but it does require cell membrane for example they are called proteins which are called carrier...
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